[The effects of enamel matrix derivative (EMD) on osteoblastic cells]

Enamel matrix derivative (EMDOGAIN, EMD) has been clinically used to promote regeneration of periodontal tissue, including cementum, periodontal ligament (PDL), and alveolar bone. However, it has not been clear whether EMD directly affects osteoblastic cells. To answer this question, we examined EMD effects on bovine PDL cells, rat and mouse bone marrow cells (RBM cells and MBM cells, respectively), and mouse osteoblastic cells (Kusa/A 1 cells). EMD was dissolved in 10 mM acetic acid and added to the culture medium at a final concentration of 50 micrograms/ml. EMD stimulated mineralized-nodule formation of PDL cells, RBM cells, and Kusa/A 1 cells. In Kusa/A 1 cells, EMD enhanced ALP activity, together with DNA content. Northern blotting analysis on Kusa/A 1 cells demonstrated stimulatory effects of EMD on the gene expression of type I collagen and osteopontin. Further, application of EMD on MBM cell culture, under 1,25(OH)2 vitamin D3 supplementation, stimulated osteoclast-like cell formation. These results indicate that osteoblastic cells respond to EMD, and that EMD would be potentially useful for bone regeneration.